1. Field of the Invention
The present invention relates to an apparatus and method for processing video data, and more particularly, to an apparatus and method for reproducing video data capable of effectively post-processing video data, using a motion vector and a difference video signal. The present application is based on Korean Patent Application No. 2002-3867, which is incorporated herein by reference.
2. Description of the Related Art
In general, a video reproduction apparatus carries out a decoding process of decoding a compressed video signal which is input as a bit stream, and a post-processing process in which a video signal is filtered to remove edge noise, blocking artifacts, and ringing artifacts therefrom, thereby improving the quality of a decoded video signal. The decoding process and the post-processing process are separately performed.
FIG. 1 is a block diagram of a conventional video reproduction apparatus. The conventional video reproduction apparatus receives a video signal output from a video encoder (not shown), and the video encoder compresses the received video signal. To compress the video signal, the video signal undergoes a discrete cosine transform (DCT) process and is then quantized. The quantized video signal undergoes a motion vector estimation and a variable-length coding (VLC) process, and then is converted into a bit stream format.
Referring to FIG. 1, a variable length decoding (VLD) unit 110 detects a quantized DCT coefficient and a motion vector obtained through a VLD process.
An inverse quantizer 120 inversely quantizes the quantized DCT coefficient and the motion vector, which are obtained by the VLD unit 110, and produces DCT coefficients.
An inverse DCT (IDCT) unit 130 performs an IDCT on the DCT coefficient produced by the inverse quantizer 120 to convert the DCT coefficient into a difference video signal. The difference video signal is produced during an inter frame encoding process. The inter frame encoding process encodes a difference video signal and a motion vector between a previous frame. Also, the intra frame encoding process encodes video signals for one frame.
An adder 140 adds the difference video signal produced by the IDCT unit 130 and a video signal produced by a motion compensating unit 160.
A motion compensating unit 160 compensates for the motion of a video signal based on information on the motion vector produced by the VLD unit 110 and the decoded video signal.
A post-processing unit 150 post-processes the decoded video signal using a filter and the like, to improve the quality of the decoded video signal.
In conclusion, the conventional video reproduction apparatus shown in FIG. 1 post-processes the video signal, which was decoded via the VLD unit 110, the inverse quantizer 120, the IDCT unit 130, and the adder 140, using the post-processing unit 150, and outputs the post-processed video signal to a display unit (not shown). The post-processing unit 150 of the conventional video reproduction apparatus of FIG. 1, however, requires a large amount of calculation to display a moving image in real time, thereby overloading the video reproduction apparatus.